Doweling machine



8- 25, 1964 R. HUGHES 3,145,389

DOWELING MACHINE Filed Jan. 26, 1962 s Sheets-Sheet 2 92 INVENTOR.

RALPH Hus/45s i/wf/of 82 ATTORNEY Flg. 4.

Bl BY 9| Aug. 25, 1964 R. HUGHES 'DOWELING MACHINE 3 Sheets-Sheet 3 Filed Jan. 26, 1962 INVENTOR. RALPH HUGHES WITNESS ATTORNEY United The present invention relates to a doweling machine and more particularly to a dowel feeding magazine and dowel-driving mechanism for a doweling machine.

The object of this invention is to provide a dowelfeeding mechanism for a doweling machine in which the dowels are automatically fed into the dowel-driving position as well as supported against buckling during the dowel-driving operation. Further objects of this invention are to provide such a mechanism which is simple and effective and will provide a maximum of continuous trouble-free operation. In accordance with the present invention, this has been accomplished by the provision of a mechanism comprising a dowel-feeding unit, which unit is laterally movable between a dowel-feeding position in which the dowels are dropped into a dowel-receiving groove and a dowel-driving position in which the dowelreceiving groove is closed by a portion of the unit having a maximum of support against deflection, and which unit is guided in its lateral movement and actuated by spaced cam means to insure against binding of the dowelfeeding unit in the lateral movement thereof.

Having in mind the above and other Objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings in which:

' FIG. 1 is an elevational view of a doweling machine embodying the present invention.

FIG. 2 is a fragmentary sectional view taken substantially on the line 22 of FIG. 1.

FIG. 3 is a fragmentary sectional view taken substantially on the line 33 of FIG. 2.

FIG. 4 is a fragmentary sectional view similar to a portion of FIG. 2 but illustrating the parts in a different operative position.

FIG. 5 is an exploded perspective view of the parts of the dowel-feeding unit.

With reference to the drawings, the present invention is illustrated in a doweling machine for forming a composite wooden panel that is used for example in flooring.

The machine includes a fabricated frame comprising an I-beam 1 having a wear plate 2 secured to the upper horizontal flange thereof. On the one end of the I-beam 1 is secured a transverse plate 3 which is secured to a work-supporting table 4 that includes vertical legs 5 and horizontal upper and lower cross pieces 6 and 7.

The table 4 includes a bed-plate 8 upon which is mounted the work W which consists of a plurality of wood as shown. The bed plate 8 is mounted for vertical adjustment on screws 9 which are held against rotation and which are mounted in threaded bushings 1t rotatably mounted in a plate 11. The bushings 10 include sprockets 12 about which is run a chain 13 that is also engaged with a drive sprocket 14 on a gear box 15 and driven by a hand wheel 16. The gear box 15 is secured to an upper cross piece 6 by means of screws 17 that extend through slots 18 in the cross piece 6, thereby providing for adjustment to tighten the chain 13. Depending from the bed plate 8 are webs 19 which are secured to the table 4 by means of bolts 29 extending through vertical slots 3,145,389 Patented Aug. 25, 1964 21 in the webs 19. To eflect a vertical adjustment of the bed plate, the bolts 20 are loosened and the hand wheel 16 is turned. The bolts 20 are then re-tightened to lock the bed plate in the adjusted position. This adjustment provides for placing the dowel in the center of the work, thereby accommodating work of different thicknesses.

The work W is clamped down on the bed-plate 8 by a plate 22 that is forced downwardly by a hydraulic cylinder 23 carried by a bracket 24 overhanging the work and mounted on the table 4 by a vertical arm 25 and by a vertical plate 26 that rises from the wear-plate 2 to a point above the bed plate 8. The work W is clamped horizontally against the plate 26 by a plate 27 that is forced toward the plate 26 by a hydraulic cylinder 28 carried by the arm 25.

The drilling and dowel-driving mechanism is mounted on a vertical movable carriage 29 which includes a vertical plate 30 disposed in engagement with the plate 26 and guided for vertical movement relative thereto by guide brackets 31, FIG. 3, which define a channel in which the plate 30 is received. Opposed to the plate 30 is a similar vertical plate 32. Secured to the lower ends of the plates 30 and 32 are a pair of cam plates 33 which are arranged vertically upon opposite sides of the wearplate 2 and are adapted to move vertically relative thereto. The cam plates 33 are formed with cam slots 34 that receive cam rollers 35 carried by slide blocks 36 mounted for horizontal sliding on the wear-plate 2. Sliding movement is imparted to the slide blocks 36 by a hydraulic cylinder 37 mounted on the wear-plate 2. It will be seen that, upon movement of the slide blocks 36, the cooperation of the cam rollers 35 with the cam slots 34 will cause the carriage 29 to move vertically. The construction is such that, in the raised position as indicated in FIG. 1, the drilling unit is aligned with the center of the work and, in the lowered position as indicated in dotted lines in FIG. 1, the dowel driving unit is aligned with the hole formed in the work by the drilling unit.

The upper portion of the carriage 29 includes a pair of opposed vertically-arranged side plates 33 mounted at their ends on the plates 30 and 32. Between the side plates 38 adjacent to the bottom thereof and at the end adjacent to the plate 32 is a housing 39 that slidably receives the drilling unit which includes a rotatable spindle 40, to which rotation is imparted by an electric motor 41 mounted on a horizontal support plate 42 extending between the plates 30 and 32 and having a drive shaft 43 on which is a sprocket 44 connected by a belt 45 to a sprocket 46 that is splined to the spindle 40 to impart rotation thereto while permitting endwise movement of the spindle relative to the sprocket. At its forward end, the spindle 40 is provided with a chuck 47 for mounting a drill 48. Endwise movement is imparted to the drilling unit by a hydraulic cylinder 48 mounted on the plate 32 and connected to an arm 50 depending from the unit through a slot (not shown) in the housing 39, thereby holding the unit against turning in the housing.

The dowel-driving mechanism comprises a hydraulic cylinder 51 mounted on the plate 32 above the cylinder 49 and having a dowel-driving rod 52 that extends forwardly on an axis parallel to the axis of the drill unit and spaced directly above the same. The end of the rod 52 enters a bore 53 in a block 54 disposed between the side plates 38. The block 54 has an extended reduced portion 55 that enters into a slot 56 in the plate 26, which slot 56 is elongated vertically to accommodate the movementof the portion 55 as the carriage is moved vertically. The dowels 58 are fed automatically by a dowel-feeding mechanism comprising a hopper 59 into which the dowels are loaded and which includes a downwardly extending chute 60 that is sufficiently wide to accommodate a single dowel. The hopper is supported by end plates 61 carried by brackets 62 that are secured by screws 63 to the top of the side plate 38 of the carriage 29. To encourage the dowels in the hopper 59 to enter the chute they are agitated by arms 64 that are mounted on a shaft 65 journaled for oscillation in brackets 66 at the rear of the hopper and extend through the open back of the hopper into engagement with the dowels. Oscillation is imparted to the shaft 65 by a crank arm 67 pivotally connected at its free end to one end of a link 68, the opposite end of which is pivotally anchored to the frame by means of a bracket 69 on the guide brackets 31. Thus, as the carriage moves vertically, the arms 64 move between the full line and the dotted line positions as illustrated in FIG. 2.

The block 54 has a stepped top which includes an upper surface 70, a lower surface 71 and a shoulder 72 between the two. More particularly, the upper surface 78 extends longitudinally along the one side for the full length of the block 54 and, at the ends thereof, for the full width of the block while the lower surface 71 extends parallel to the upper surface longitudinally along the other side of the block but intermediate the ends of the block, thereby forming end portions having an upper surface continuous with the upper surface and forming end shoulders 73 and 74 that rise between the surfaces 70 and 71. The lower surface 71 is open on the one side of the block 54 and is disposed to intersect the top of the bore 53 which is routed to form a dowel-receiving groove 75.

The dowel-feeding unit comprises a dowel-supporting plate 76 and a dowel-feeding plate 77. The dowel-supporting plate 76 extends through a slot 78 in the side plate 38 and rests on the lower surface 71. The shoulders 72, 73 and 74 are provided with an undercut groove 79 in which the edge of the plate 76 is seated. Outwardly of the side plate 38, the plate 76 has a depending lug 80 in which are formed two grooves 81 that receive the upper edge of brackets 82 secured by screws 83 to the side plate 38. The plate 76 is thus supported for sliding laterally of the block 54 between a dowel-driving position as illustrated in FIG. 2, during which the dowel-driving rod 52 is advanced, and a dowel-feeding position as illustrated in FIG. 4, in which a dowel is dropped into the dowel-receiving groove 76. In the dowel-driving position, the plate 76 is disposed over and thus closes the open upper portion of the groove 75 to confine the dowel and thereby prevent buckling of the same as it is being driven. At this time, the edges of the plate 76 are seated in the groove 79 which, together with the slot 78, support the plate against yielding vertically.

The dowel-feeding plate 77 is mounted on the upper surface 70 and on the top edge of the side plate 38 for unitary lateral movement with the dowel-supporting plate 76. The brackets 62 have recesses 83 on the bottom thereof which, together with the underlying portion of the upper surface 70 of the block 54 define slots which receive tongues 84 extending from the ends of the plate 77 The slots thus formed are wider than the tongues 84 by an amount sufficient to accommodate lateral movement of the plate 77 between the dowel-driving position, FIG. 2, and the dowel-feeding position, FIG. 4. The plate 77 is provided with a dowel-receiving slot 85 which, in the dowel-driving position is disposed beneath the chute 60 to receive the lowermost dowel in the chute. At this time, the slot 85 is closed at the bottom by the upper surface 70 of the block 54. When the plate 77 is moved to the dowel-feeding position, the slot 85 is moved off the upper surface 70 and over the groove 75 in the block 54 so that the dowel therein will drop into the groove. The thickness of the plate 77 is substantially equal to the dowel diameter so that the plate 77 can be moved laterally under the stack of dowels in the chute 60, thus removing the lowermost dowel by means of the slot 85 while the portion of the plate 77 beyond the slot 85 moves under and supports the remaining dowels.

The dowel-supporting plate 76 and the dowel-feeding plate 77 are spaced apart vertically to accommodate a cam plate 86 by means of which lateral movements are imparted to the plates. The cam plate 86 is provided with a pair of spaced identical cam slots 87 in which is disposed cam followers in the form of rollers 88. Shoulder screws 89 extend through aperture 90 in the dowelfeeding plate 77, through the hub of the rollers 88, and are threaded into aperture 91 in the dowel-supporting plate 76. The cam plate 86 is confined between the outer surface of the side plate 38 and upstanding lugs 92 on the brackets 82 for endwise movement in a direction normal to the direction of lateral movement of the plates 76 and 77 Endwise movement is imparted to the cam plate 86 by a hydraulic cylinder 93 mounted on the side plate 38 and connected to the cam plate 86 by a piston rod 94. The configuration of the cam slots 87 is such as to move the plates 76 and 77 to the dowel-driving position, FIG. 2, when the cam plate 86 is moved to the right as seen in FIG. 3 to position the cam rollers 88 in the ends 95 of the cam slots, and to move the plates 76 and 77 to the dowel-feeding position, FIG. 4, when the cam plate 86 is moved to the left as seen in FIG. 3 to position the cam rollers 88 in the ends 96 of the cam slots.

The dowel-supporting plate 76, in the area above the groove 75 is backed up by a lug 97 integral with and depending from the dowel-feeding plate 77, thus providing additional support against yielding vertically during the dowel-driving operation.

The machine also includes a source of hydraulic pressure, together with various controls, all of which may be of conventional construction and are not herein shown.

The operation of the machine is as follows. After the work W is loaded onto the bedplate 8, a start switch 98 is pushed. Through solenoid actuated valves, the hydraulic cylinders 23 and 28 are connected to the source of hydraulic pressure, and the work is clamped both horizontally and vertically on the bed plate 8, and, simultaneously, hydraulic pressure is applied to the cylinder 93 to actuate the cam plate 86 which, through the cam slots 87 and rollers 88 moves the dowel-feeding plate 77 into the dowel-driving position as shown in FIG. 2. In this position of the plate 77 another dowel drops from the chute 69 into the slot 85, and the dowel-supporting plate 76 is in position to close the open upper portion of the groove 75 to support the dowel against buckling as it is driven. A safety switch 104 is disposed to sense the position of the dowel-feeding plate 77 so that if it is not completely returned, as would be the case if the dowel is not properly seated in the groove 75 and thus prevents seating of the plate 76, the machine is stopped. This is to prevent jamming which would occur during the dowel-driving operation if the dowel were not properly seated in the groove 75. A pressure-sensitive valve is used to actuate the hydraulic cylinder 37 as soon as the desired clamping pressure is applied to the work.

Upon actuation of the cylinder 37, the slide blocks 36 are forced to the left into the position illustrated in FIG. 1, and thus, through the cam rollers 35 and cam slots 34 raise the carriage 29 to the drilling position. Mounted upon the I-beam 1 is a limit switch 99 which is adapted to be closed by an arm 100 on the cam plate 33 when the carriage 29 has risen to the drilling position. The switch 99, through a solenoid actuated valve, applies hydraulic pressure to the cylinder 49 which advances the drill unit 39. The motor 41 runs constantly during the operation of the machine so that as the drill unit advances, the drill bores a hole in the work W. The drill unit 39 carries a trip arm 101 which, when the drill has advanced to the desired depth in the work, opens a limit switch 102 which reverses the application of pressure to the cylinder 49, thereby retracting the drill unit. When the drill has been withdrawn, the trip arm 101 opens a second limit switch 103 that reverses the cylinders 37 to lower the carriage 29.

When the carriage 29 has dropped into the dowel-driving position, illustrated in dotted lines in FIG. 1, in which the dowel-driving mechanism is aligned with the hole drilled in the work, the arm 100 trips a limit switch 105 which, through a solenoid actuated valve, applies hydraulie pressure to the cylinder 51 to advance the dowel-driving rod 52. Movable with the dowel-driving rod 52 is a trip arm 106 which trips a limit switch 107 when the rod 52 has advanced to the desired point. When the switch 107 is tripped, the pressure on the cylinder 51 is reversed to retract the rod 52 and, when it returns, trips a limit switch 108. The switch 108 reverses the application of pressure on the clamping cylinders 23 and 28 and the dowel-feeding cylinder 93 to release the work and to move the plate 77 into the dowel-feeding position as seen in FIG. 4, and then stops the machine.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of my invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.

Having thus set forth the nature of the invention, what I claim herein is:

1. In a doweling machine, a dowel-feeding mechanism comprising a block having a stepped top including an upper surface and a lower surface and a shoulder between said surfaces, said lower surface having an upwardlyopen dowel-receiving groove adjacent said shoulder, a dowel-feeding unit having a dowel-feeding portion on said upper surface and having a dowel-receiving slot and a dowel-supporting portion on said lower surface, means for mounting said dowel-feeding unit for lateral movement between a dowel-driving position in which said slot is disposed over and is closed at the bottom by said upper surface and in which said dowel-supporting portion is dis posed over and closes the open upper portion of said groove and a dowel-feeding position in which said slot is disposed over said groove and said dowel-supporting portion is retracted from over said groove for permitting a dowel to drop from said slot into said groove, an undercut groove in said shoulder for seating therein an edge portion of said dowel-feeding unit in the dowel-driving position, means for imparting actuation to said dowelfeeding unit, and a hopper disposed above said dowelfeeding portion and adapted to feed dowels into said slot when in the dowel-driving position.

2. A dowel-feeding mechanism in accordance with claim 1 in which said means for imparting actuation to said dowel-feeding unit comprises a cam plate, means for mounting said cam plate for endwise movement in a direction normal to the direction of movement of said dowel-feeding unit, said cam plate having a pair of cam slots, a follower disposed in each of said cam slots, means for securing said followers to said dowel-feeding unit at spaced points, and means for imparting endwise movement to said cam plate.

3. In a doweling machine, a dowel-feeding mechanism comprising a block having a stepped top including an upper surface and a lower surface and a shoulder between said surfaces, said lower surface having an upwardlyopen dowel-receiving groove adjacent said shoulder, a dowel-feeding plate on said upper surface and having a dowel-receiving slot, a dowel-supporting plate on said lower surface, means for mounting said dowel-feeding plate and said dowel-supporting plate for lateral movement between a dowel-driving position in which said dowel-feeding plate is disposed with said slot over and closed at the bottom by said upper surface and in which said dowel-supporting plate is disposed over and closes the open upper portion of said groove and a dowel-feeding position in which said dowel-feeding plate is disposed with said slot over said groove and said dowel-supporting plate is retracted from over said groove for permitting a dowel to drop from said slot into said groove, an undercut groove in said shoulder for seating therein the edge of said dowel-supporting plate in the dowel-driving position, means for imparting unitary actuation to said dowelfeeding plate and said dowel-supporting plate, and a hopper disposed above said dowel-feeding plate and adapted to feed dowels into said slot when in the dowel-driving position.

4. A dowel-feeding mechanism in accordance with claim 3 in which said means for imparting actuation to said dowel-feeding plate and said dowel-supporting plate comprises a cam plate disposed between said dowel-feeding plate and said dowel-supporting plate, means for mounting said cam plate for endwise movement in a direction normal to the direction of movement of said dowelfeeding plate and dowel-supporting plate, said cam plate having a pair of cam slots, a cam follower disposed in each of said cam slots, means for securing said cam followers to said dowel-feeding plate and said dowel-supporting plate, and means for imparting endwise movement to said cam plate.

Doman Dec. 17, 1895 Tozzi July 30, 1918 

1. IN A DOWELING MACHINE, A DOWEL-FEEDING MECHANISM COMPRISING A BLOCK HAVING A STEPPED TOP INCLUDING AN UPPER SURFACE AND A LOWER SURFACE AND A SHOULDER BETWEEN SAID SURFACES, SAID LOWER SURFACE HAVING AN UPWARDLYOPEN DOWEL-RECEIVING GROOVE ADJACENT SAID SHOULDER, A DOWEL-FEEDING UNIT HAVING A DOWEL-FEEDING PORTION ON SAID UPPER SURFACE AND HAVING A DOWEL-RECEIVING SLOT AND A DOWEL-SUPPORTING PORTION ON SAID LOWER SURFACE, MEANS FOR MOUNTING SAID DOWEL-FEEDING UNIT FOR LATERAL MOVEMENT BETWEEN A DOWEL-DRIVING POSITION IN WHICH SAID SLOT IS DISPOSED OVER AND IS CLOSED AT THE BOTTOM BY SAID UPPER SURFACE AND IN WHICH SAID DOWEL-SUPPORTING PORTION IS DISPOSED OVER AND CLOSE THE OPEN UPPER PORTION OF SAID GROOVE AND A DOWEL-FEEDING POSITION IN WHICH SAID SLOT IS DISPOSED OVER SAID GROOVE AND SAID DOWEL-SUPPORTING PORTION IS RETRACTED FROM OVER SAID GROOVE FOR PERMITTING A DOWEL TO DROP FROM SAID SLOT INTO SAID GROOVE, AN UNDERCUT GROOVE IN SAID SHOULDER FOR SEATING THEREIN AN EDGE PORTION OF SAID DOWEL-FEEDING UNIT IN THE DOWEL-DRIVING POSITION, MEANS FOR IMPARTING ACTUATION TO SAID DOWELFEEDING UNIT, AND A HOPPER DISPOSED ABOVE SAID DOWELFEEDING PORTION AND ADAPTED TO FEED DOWELS INTO SAID SLOT WHEN IN THE DOWEL-DRIVING POSITION. 